This invention relates to an electric machine, for example a generator suitable for use in aerospace applications, and to a rotor suitable for use in such an application.
In aerospace applications, it is common for the rotor of a generator to rotate at high operating speeds, for example at speeds in excess of 24000 rpm. As tight volume and weight constraints apply to components for use in aerospace applications, it is desirable to provide an electrical generator which is capable of producing a high output without significantly increasing the dimensions of the generator.
Existing generator rotors have been designed in such a way that flux saturation of parts of the rotor material occurs. In order to increase the available output of the generator, it is desirable to increase the amount of pole material without increasing the overall dimensions of the rotor. It is an object of the invention to provide an electric machine and a rotor for use therein which permits the amount of pole material to be increased for a rotor of given dimensions.